Despite decades of progress in broadband access technology, the demand for emerging applications by end users continues to stress the data rates and flexible ability of existing wireless and wired broadband access solutions. See, for example, P. Odling, T. Magesacher, S. Host, P. O. Borjesson, M. Berg, and E. Areizaga, “The fourth broadband concept,” IEEE Commun. Mag., vol. 47, no. 1, pp. 63-69, January 2009 and J. E. Mitchell, “Radio over fiber networks: Advances and challenges,” presented at the ECOC Conf., Vienna, Austria, 2009, Paper P2.4.5.A.
On the wireline side, Ethernet networks operating at 40 Gb/s and 100 Gb/s per link for metro and long-haul area have gained tremendous momentum in technical and market viability research in recent years, and extensive development on interface specifications and standardization efforts are under way. In addition to the metro and long-haul application, another important market area is data center and high performance computing with very-short-reach (VSR) capability. A 10-Gb/s wireless data rate is expected for bridging 10-Gb/s Ethernet links for future personal computer (PC)-to-PC and server-to-server communications without cables; and provide backup and redundancy services for temporary restoration in a disaster recovery scenario.
Radio-over-fiber is considered to be a good solution to provide broadband optical wireless services, as described in Ng'oma et al., “Simple Multi-Gbps 60 GHz Radio-over-Fiber Links Employing Optical and Electrical Data Up-conversion and Feed-Forward Equalization,” Proc. OFC, OWF2 (2009); C. T. Lin et al., “Ultra-high Data-rate 60 GHz Radio-over-Fiber Systems Employing Optical Frequency Multiplication and OFDM Formats,” IEEE/OSA Journal of Lightwave Technology, vol. 28, No. 16, pp. 2296-2306, Aug. 15, 2010; K. I. Kitayama and R. A. Grifin, “Optical downconversion from millimeter-wave to IF-Band over 50 km long optical fiber link using an electroabsorption modulator,” IEEE Photon. Technol. Lett., vol. 11, no. 2, pp. 287-289, February 1999; Z. Xu, X. Zhang, and J. Yu, “Frequency upconversion of multiple RF signals using optical carrier suppression for radio over fiber downlinks,” Opt. Exp., vol. 15, no. 25, pp. 16737-16747, 2007; J. Yu, G. K. Chang, Z. Jia, et al., “Optical Millimeter Technologies and Field Demonstrations for Very High Throughput Wireless-Over-Fiber Access Systems”, Journal of Lightwave Technology, Vol. 28, Issue 16, pp. 2376-2397 (2010); I. G. Insua, D. Plettemeier, and C. G. Schäffer, “Radio-over-fiber-based wireless access with 10 Gbits/s data rates” Journal of Optical Networking, Vol. 8, Issue 1, pp. 77-83 (2009); M. Weib et al., “60-GHz photonic millimeter-wave link for short- to medium-range wireless transmission up to 12.5 Gb/s,” IEEE J. Lightw. Technol., vol. 26, no. 15, pp. 2424-2429, Aug. 1, 2008; and A. Chowdhury, J. Yu, H. C. Chien, M.-F. Huang, T. Wang, G.-K. Chang, “Spectrally efficient simultaneous delivery of 112 Gbps baseband wireline and 60 GHz MM-wave carrying 10 Gbps optical wireless signal in radio-over-fiber WDM-PON access systems”, ECOC 2009, 4.5.1.
Recently, an access system with 60-GHz mm-wave Radio-over-fiber (RoF) carrying 10-Gb/s On/Off keying (OOK) data for short-range wireless transmission and 100-Gb/s wire-line downstream and 10-Gb/s wireline upstream has been demonstrated, as described in A. Chowdhury, J. Yu, H. C. Chien, M.-F. Huang, T. Wang, G.-K. Chang, “Spectrally efficient simultaneous delivery of 112 Gbps baseband wireline and 60 GHz MM-wave carrying 10 Gbps optical wireless signal in radio-over-fiber WDM-PON access systems”, ECOC 2009, 4.5.1.